Psychiatrists and other doctors in Chicago and across the country have been caught helping immigrants gain U.S. citizenship by providing fake medical opinions, records show.

An estimated 1,000 people a year submit a form to immigration officials in Chicago alone to waive the requirements that someone seeking citizenship must understand English and pass a test in U.S. history and civics.

The obscure Form N-648 requires a doctor to list any physical or mental ailment that would prevent a patient from meeting the language requirements of citizenship.

The form is susceptible to fraud, though. Immigration officials aren’t supposed to investigate the ailments. They’re instructed only to make sure that the forms are completed correctly and that the information in an applicant’s file is consistent.

Corrupt doctors have taken cash to fill out the forms for able-bodied immigrants, who then avoid having to take proficiency tests in English and U.S. history and civics. Three doctors with Chicago offices have pleaded guilty to the scam, and another is facing charges.

Dr. Slawomir Puszkarski.

Dr. Slawomir Puszkarski, whose practice on Milwaukee Avenue on the Northwest Side catered to Polish patients, was sentenced to probation in 2015 after he admitted helping an undercover federal agent submit a fake Form N-648.

“I learned a lot from my mistake, and I would never do it again,” the 55-year-old psychiatrist told the Chicago Sun-Times.

Other doctors recently have faced prosecution for the crime in San Diego, Miami and Philadelphia, records show — part of a larger problem of fraud involving immigration documents. For years, fake ID-makers have flourished in Illinois and elsewhere.

But fraud involving Form N-648 is different because the doctors take a bigger risk than most scammers — that of losing their medical license — in exchange for fees that records show have ranged from about $200 to $2,500 a form.

Dr. Fernando Mendez-Villamil.

In some cases, the doctors who engage in such fraud also were scamming Medicaid and Medicare. Dr. Fernando Mendez-Villamil, a Miami psychiatrist now serving a 151-month prison sentence, made false diagnoses of mental illnesses, allowing clients to obtain Social Security disability payments, according to prosecutors. They say his clients also used fake mental diagnoses on N-648 forms to become citizens.

The 50-year-old doctor was ordered to repay the government more than $30 million. Authorities seized his property and an art collection that included prints by Marc Chagall.

On the West Coast, Dr. Roberto J. Velasquez was sentenced to 21 months in prison in 2013 for immigration and Social Security fraud in the San Diego area. Velasquez, a psychiatrist, falsified N-648 forms between 2006 and 2012 in return for $200 each, prosecutors said. The forms granted disability exemptions to at least 50 people, records show.

Velasquez, 60, coached clients to use poor English during citizenship interviews and not to disclose their college educations.

In 2011, an undercover agent visited his office.

“All right, very good, we’re going to make you a United States citizen, OK?” Velasquez was secretly recorded saying.

“I’m going to put down that you’re depressed, sad, anxious, um, I’m going to make a good report for you.”

Puszkarski, the Chicago psychiatrist busted for citizenship fraud involving the N-648 forms, is a Polish immigrant who became a U.S. citizen.

In December 2011, an undercover agent came to him seeking a phony Form N-648. Puszkarski referred the agent to Dr. Jerry Jakimiec, who posed as the agent’s regular physician and created a fake record of medical care, court records show. Without giving an exam, Jakimiec certified that the agent suffered from depression and arteriosclerosis.

Jakimiec sought out such shady business, according to federal authorities, who said he even placed an ad in a Polish-language directory that said, “We have the best attorneys, we work on immigration matters — examination for green card, we take care of it for you so you don’t have to take exams for citizenship.”

Then, in July 2012, Puszkarski certified on Form N-648 that the same agent suffered from depression, even though the psychiatrist never did an exam, either. The agent paid Puszkarski $2,520 for the illegal assistance.

In 2015, Jakimiec pleaded guilty to immigration fraud, along with ripping off Blue Cross and Blue Shield of Illinois with false billings. He was sentenced to three years in prison and ordered to pay $258,000 in restitution.

Jakimiec, 62, is serving his sentence in the federal prison in Oxford, Wisconsin.

Puszkarski also pleaded guilty and was sentenced to probation and ordered to pay a $10,000 fine. Prosecutors said he was motivated by “hubris and greed.”

Illinois state officials suspended the medical licenses of Jakimiec and Puszkarski because they pleaded guilty to felonies. Puszkarski’s Wisconsin license was also suspended.

In December, Puszkarski filed a petition to restore his Illinois medical license. A hearing on his petition is scheduled for Monday, records show.

“I thought I was helping people,” he told the Sun-Times. “I didn’t go in there to defraud the government.”